High temperature hydrocarbon defoamer composition and method

ABSTRACT

Methods and compositions for controlling foam in high temperature hydrocarbons during processing animal oils, exemplified by mink oil, are added to the hydrocarbon to control foam.

FIELD OF THE INVENTION

The present invention pertains to compositions and methods forcontrolling foaming in hydrocarbon fluids undergoing high temperatureprocessing.

BACKGROUND OF THE INVENTION

Foaming problems can occur during the high temperature processing ofhydrocarbon fluids. Crude oil towers and cokers operating at hightemperatures can produce foam in their hydrocarbon products which inturn diminishes the efficiency of the tower or coker, degrading thequality of the overhead products such as gasoline and gas oils. Severefoaming problems are often encountered in crude oils during separationof dissolved gases at the well-head.

In the processing of various residual petroleum stocks into coke, acommonly used technique is the well known delayed coking process. In thedelayed coking process, heavy residual oils are heated to about 500° C.by pumping them at high velocity through a pipe furnace and thencharging these oils to an insulated coking drum. The delayed cokingprocess produces a quantity of foam which is undesirable since itdiminishes the efficient operation of the process.

Other refinery processes that can experience foaming problems includecrude units, vacuum units, vis breakers, delayed cokers and asphaltprocessing units. Traditionally, silicone (dimethyl polysiloxane) basedantifoam compounds were employed to treat these operations for foamingproblems.

The use of silicone-based defoaming compounds is economically attractivedue to their low dosage levels in the hydrocarbons. However, they pose aproblem in being expensive with respect to using them in less expensivehydrocarbon fluids. The silicone-based compounds also pose a problem dueto their difficulty in dispersing in high temperature hydrocarbonsystems. The silicone-based compounds tend to react with the metalsurfaces of the processing system. Another problem that is significantto the oil industry is that silicone-based defoamers poison downstreamcatalysts with silicon carryover and residues.

SUMMARY OF THE INVENTION

This present invention relates to compositions and methods forcontrolling foaming in hydrocarbon fluids undergoing high temperatureprocessing employing an animal oil.

Animal oils are those oils derived from the glands of mammals. Thepreferred animal oil is mink oil which is derived from the scent glandof the mink.

DESCRIPTION OF THE RELATED ART

U.S. Pat. No. 2,862,885, Nelson et al., teaches a hydrocarbon oil whichcontains a homopolymer of a monovinylalkoxysilane to inhibit foaming ofthe hydrocarbon oil. U.S. Pat. No. 3,652,453, MacDonnell, teaches aprocess for preparing a defoamer composition for hydrocarbon oil basesystems. This composition comprises a quick-chilled mixture ofhydrocarbon waxes and/or amides and organic polymers in an inert liquidvehicle. Additionally, castor oil, silicone oil, water, an alkyleneoxide-castor oil reaction product, and a sulfonated naphthalenecondensate may be added to the hydrocarbon oil.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to compositions and methods forcontrolling foam in high temperature hydrocarbon fluids duringprocessing comprising adding an effective amount of an animal oil.

The preferred animal oil is mink oil. This is a commercially availableoil which can be purchased, for example, from Croda, Inc. The mink oilin both pure and refined grades controlled foaming during laboratorytesting.

"High temperature" is meant to include those hydrocarbons beingprocessed at a temperature from about 300° F. to about 1000° F.Distillation of crude oils and coking of crude oils frequently occur attemperatures from 600° F. to 1000° F.

The animal oil may be added to the hydrocarbon fluid that isexperiencing foaming problems in neat form, or in any suitable solvent.Representative solvents include naphtha, or any organic oil which iscompatible with the hydrocarbon being treated.

The preferred embodiment of this invention is mink oil either in anunrefined (pure) form or diluted with organic solvent. One advantage ofemploying mink oil is its low viscosity which eliminates the need todilute the oil, makes it easier to handle and allows its use withsmaller pumps. These oils may also prove to be environmentally cleanerto produce than chemical based alternatives.

The animal oils can be applied at any stage of the hydrocarbonprocessing system experiencing foaming. It is preferred that the oils beapplied either upstream of the site experiencing foaming problems ordirectly to the site of the problem.

The animal oils may be applied to the hydrocarbon being treated assolutions with concentrations ranging from 1% to 100% active with 10% to100% being the preferred range. This would convert into a dosage rate of10 parts to about 1000 parts per million parts hydrocarbon. Specificdosages are determined by the conditions existing in the particularhydrocarbon processing system. It is to be understood that our inventionis not to be limited by the dosage of the animal oil.

The treatments of the instant invention can be applied to thehydrocarbon processing system along with other hydrocarbon treatmentprograms. Representative additives include antifoulants and corrosioninhibitors.

In order to more clearly illustrate this invention, the data set forthbelow was developed. The following examples are included as beingillustrations of the invention and should not be construed as limitingthe scope thereof.

EXAMPLES

The animal oils of the instant invention were evaluated for their foamcontrol ability in the high temperature defoamer test. The testprocedure is described below.

A 500 ml borosilicate glass cylinder is charged with 250 ml coker feed.The sample is sparged slowly (100-200 ml/min) with nitrogen using asubmerged borosilicate tube with a fine pore fritted gas diffuser.

The sample is then heated with an electric mantle to the temperature ofthe unit. (Typically 700°-900° F. for a coker drum). As the sampleapproaches the temperature of the unit (within 50° F. of 800° F.), thenitrogen flow is increased to bring the foam height above the 500 mlmark.

The defoamer is added as a dilute solution (about 1% active) from aweighed syringe at a rate which maintains the foam height at the 500 mlmark. The time of first injection is recorded. After timing for 2 to 60minutes, the syringe is reweighed, and the usage recorded. The longerthe duration of the test, the more accurate the result is.

The distillate collected can be analyzed for chemical carryover ifdesired. The residue can be allowed to completely coke and the cokeanalyzed for quality if desired. The results of this testing arepresented in Table I.

                  TABLE I                                                         ______________________________________                                        High Temperature Defoamer Test                                                Texas Refinery Coker Feed                                                     Treatment Agent                                                                             Usage (mg active/min)                                           ______________________________________                                        A              0.035                                                          B             0.48                                                            C             0.38                                                            D             0.28                                                            ______________________________________                                         A is dimethylpolysiloxane in aromatic solvent                                 B is polyisobutylene in aromatic solvent                                      C is a sulfonated hydrocarbon compound in aromatic solvent                    D is Mink oil                                                            

These results indicate that the animal oils of the instant inventionprove effective at controlling foam in hydrocarbon systems.

In accordance with the patent statutes, the best mode of practicing theinvention has been set forth. However, it will be apparent to thoseskilled in the art that many other modifications can be made withoutdeparting from the invention herein disclosed and described, the scopeof the invention being limited only by the scope of the attached claims.

Having thus described the invention, what I claim is:
 1. A method forinhibiting foam production in high temperature hydrocarbon fluids duringprocessing comprising adding a foam inhibiting amount of a mammal scentgland oil.
 2. The method as claimed in claim 1 wherein said mammal oilis mink oil.
 3. The method as claimed in claim 1 wherein saidtemperatures are from about 300° F. to about 1000° F.
 4. The method asclaimed in claim 1 wherein said mammal oil is added to said hydrocarbonin a suitable solvent.
 5. The method as claimed in claim 4 wherein saidsolvent is a hydrocarbon fluid.
 6. The method as claimed in claim 1wherein said mammal oil is added to said hydrocarbon in an amount of 10parts to about 1000 parts per million parts hydrocarbon.
 7. The methodas claimed in claim 1 wherein said hydrocarbon is coker fluid.
 8. Themethod as claimed in claim 1 wherein said hydrocarbon is crude oil.